1. Field of the Invention
The present invention relates to a nut lock assembly for positively retaining a nut upon a threaded shaft and more particularly relates to a nut lock assembly of the reusable, selectively removable, locking cap type for positively retaining a standard nut, such as a standard hex nut, upon an externally threaded shaft.
2. Description of the Prior Art
It is well known, of course, that bolts hold parts together by exerting pressure on the mating surfaces. Needed pressure is developed by tightening the bolt and/or tightening a nut upon the bolt. It is also well known, especially for nut and bolt assemblies utilized in modern machinery and equipment or the like which are subject to movement or vibration or other forces which may tend to cause unwanted loosening of the nut upon the bolt that it is desirable that the nut be positively locked, that is prevented from relative rotation relative to the bolt or other threaded shaft. Many types of nut lock assemblies are known in the prior art and include, among others, the locking teeth or ramp type as may be seen in greater detail by reference to U.S. Pat. Nos. 2,253,241 and 2,959,204, both of which are hereby incorporated by reference. This type of a nut lock system was not satisfactory for all purposes as the locking action required the maintenance of at least a predetermined minimum tension in the bolt and further required that the locking teeth become inbedded in a bearing surface which might be highly undesirable.
Nut lock assemblies of the locking cap type are also well known in the art as may be seen by reference to U.S. Pat. Nos. 1,105,123; 1,241,181 and 1,567,653, all of which are hereby incorporated by reference. The prior art nut lock assemblies of the locking cap type were not totally satisfactory as they did not permit locking of the nut to the bolt at relatively small incremental relative rotational positions thereof, they required specially configured nuts and/or bolts, they required rather complicated machining and/or assembly operations such as transverse boring of the nut and/or bolt, and/or they did not exert a force tending to resist loosening of the bolt upon the nut which tended to increase with increased relative rotation of the nut in the removal direction of relative rotation.